The present invention relates to telephone coupling devices for use in communications networks whereby the transducer of the telephone handset and the transducer of the acoustic coupler are maintained in effective acoustical coupling relationship.
Portable computer terminals and similar devices intended to communicate with central data processing facilities must be able to be effectively coupled to telephone lines to provide for the desired data transmission. The development and common use of telephone equipment from a variety of diverse manufacturers has created significant problems tending to reduce the effectiveness of such portable terminals because the necessity for effective coupling to the telephone handset has become a problem of some complexity and importance tending to restrict the hoped for universal usage of such portable terminals. It is not uncommon that a telephone coupler intended for a standard handset such as manufactured by Western Electric is unusuable with the increasingly common handsets identified by the general designation Trimline handsets and handphones. One typical solution of the problem involves special interface or transition units disposed between "Trimline" handsets and the coupler thereby significantly lowering the effectiveness of the sound transmission. Typical of prior art acoustic telephone couplers intended for use with telephone handsets of standard design can be found in U.S. Pat. Nos. 3,719,783, 3,733,437, and 3,992,583. Additionally, telephone couplers have been developed which are intended to be strapped to the telephone handset such as are discussed in U.S. Pat. Nos. 3,180,937, 3,299,207 and 3,619,507. Thus, the known prior art has not provided a universally useful telephone coupler which is effectively self-contained and ready for use with a variety of handsets.